1. Field of the Invention
The present invention relates to a reformer for a fuel cell system and, more particularly, to a plate type reformer.
2. Description of the Related Art
A fuel cell is a system for producing electric power by generating electric energy through the electrochemical reaction of oxygen and hydrogen contained in hydrocarbon-group materials, such as methanol, ethanol and natural gas.
A polymer electrolyte membrane fuel cell (PEMFC) has been developed recently. The PEMFC has excellent output characteristics, low operating temperature, and fast starting and response characteristics. The PEMFC may be used as a mobile power source for vehicles, as a distributed power source for homes and buildings, or as a portable power source such as for electronic devices. The PEMFC, therefore, has a wide range of applications.
The components of the PEMFC are a stack, reformer, fuel tank, and fuel pump. The stack forms an electric generating aggregate of a plurality of unit fuel cells. The fuel pump supplies fuel in the fuel tank to the reformer. The reformer reforms the fuel to create a reformed gas containing hydrogen, and supplies the reformed gas to the stack. In addition, air is supplied to the stack through a separate pump.
Accordingly, the stack generates the electric energy through the electrochemical reaction of oxygen contained in air and hydrogen contained in the reformed gas.
The reformer generates hydrogen from fuel through a chemical catalytic reaction using thermal energy, and it has a thermal source assembly for generating thermal energy. A reforming reactor is used for absorbing the thermal energy and generating hydrogen from the fuel, and a carbon monoxide reduction assembly reduces the concentration of carbon monoxide contained in the reformed gas.
However, in the reformer of the conventional fuel cell system, the thermal source assembly, reforming reactor, and carbon monoxide reduction assembly have reaction vessel shapes with predetermined inner spaces respectively. To increase the volume of the reformer, each corresponding inner space would need to be increased, creating an overall larger reformer and fuel cell. Therefore, there is a need for a compact reformer to minimize the overall fuel cell system structure.